The present invention relates to an Internet telephone adapter for setting up voice/data links in line-switching networks and packet-switching networks and, in particular, to an Internet telephone adapter for cordless applications.
The volume of voice and data links in communications networks using subscriber terminals, such as telephones, mobiles and computer units (PC), is growing at a great rate both in the business sector and in the private sector. For this continuously growing communication volume, incredible sums of money are spent every year both in the business sector and in the private sector.
Voice links normally have been set up over “line-switching networks,” where a direct (point-to-point) link, as it were, has been set up between the call parties. By contrast, for the data traffic, “data networks” have been used which, as packet-switching networks, packaged the data to be transferred into individual packets and sent them to a receiver via a wide variety of paths. Particularly as a result of the aggregation of a multiplicity of packet-switching networks in the “Internet,” a worldwide packet-switching network has been created which can be used to transfer data, particularly in a relatively inexpensive manner.
To utilize this great difference in cost between line-switching networks and packet-switching networks,. the company Vocaltec has proposed the “Internet phone,” which also permits a voice link over a packet-switching network, such as the Internet. FIG. 3 shows a simplified illustration of such an Internet phone configuration in which a voice link between two subscribers is set up over a packet-switching network 1.
In FIG. 3, a subscriber terminal TE(A) includes a computer unit PC (personal computer) which has a sound card (not shown) with a connected loudspeaker LA and a microphone MI. The computer unit PC also has a subscriber access adapter (e.g., modem), which is not shown but which is connected to a service provider 2a (SP) via a subscriber line TL. In this case, the service provider 2a, as a node in a packet-switching bidirectional communications network 1, such as the Internet, provides access to this network.
In the same way, a second call party has a subscriber terminal TE(B) having a computer unit PC and an associated sound card with a connected microphone MI and a loudspeaker LA, the computer unit PC again setting up a connection to a service provider 2b (SP), preferably via a subscriber access adapter in the form of a modem. The service provider 2b again has an access facility to the packet-switching bidirectional communications network 1.
To set up a voice link between the subscriber terminal TE(A) and the subscriber terminal TE(B) over the packet-switching network 1, the computer units PC in question are operated using a program (e.g., from Vocaltec) wherein the voice data recorded by the respective microphone are transferred, packaged into small packets, over the packet-switching network 1 and are assembled at the receiver end such that a continuous voice signal is, in turn, obtained at the loudspeaker LA. In this way, it is possible to set up an extremely inexpensive voice link throughout the world over the Internet, for example.
However, a drawback of a such a solution is that it is not possible to use conventional telephones and, hence, a connection can be set up only between two Internet telephones having appropriate computer units PC.
The document WO 98/42104 has, therefore, disclosed a system and a method for setting up a voice link over both a packet-switching network and a line-switching network which now also allow “Internet telephones” to be connected to “normal telephones.” In this context, however, the Internet telephones still include a computer-assisted system with a microphone and a loudspeaker and a specifically aligned local service provider for coupling both the line-switching data and the packet-switching data.
The document U.S. Pat. No. 5,838,665 describes another adapter apparatus which can be used to couple the Internet telephone systems described above to conventional telephones. In this context, connecting a normal telephone to an “Internet telephone system” makes it possible to provide, by way of example, multiparty services, etc., between the different systems. However, a drawback with this system is that a computer assisted terminal unit (PC) still produces the “Internet telephone,” which is why it is rejected by a large number of users.
The present invention is, therefore, directed toward providing an Internet telephone adapter for setting up voice/data links in line-switching networks and packet-switching networks which is both inexpensive and user friendly.